The invention set forth in this specification is primarily directed to control apparatus for use with stoves or cook tops employing an electrically powered energy release element or structure for heating purposes. It is considered that the invention is best adapted for use with stoves in which such an energy release structure or element is an induction heating coil, but that the invention is also applicable to other related heating apparatuses such as those employing conventional resistance heating elements.
Since the introduction of the first electrically powered stoves for cooking purposes there have been great improvements in such structures. It is considered that there still remains a distinct need for improvement in the controls or control apparatuses employed in such stoves in order to regulate the amount of heat produced during the operation of such stoves. Probably this can best be illustrated by briefly referring to common known types of controls as have been utilized with electrically powered stoves.
Up to the present virtually all types of stoves manufactured and sold have utilized a knob capable of being physically manipulated in order to rotate a shaft in order to control the operation of a heating unit. While structures of this type are unquestionably utilitarian and satisfactory it is frequently not desirable to use them. Whenever this type of control structure is used it is virtually impossible to mount the control structure on a horizontal surface where it is positioned so that it cannot be actuated by children without creating an area underneath the knob where there is apt to be an accumulation of unsightly materials. Further, whenever a structure of this type is mounted upon a horizontal surface there is danger of cleaning solutions such as soapy water seeping past a shaft used into the interior of the stove.
A recognition of these factors has led to the development of specialized type controls for use with stoves. As an example of this it is now known to magnetically couple a movable actuator for use in controlling the operation of a stove through a nonferromagnetic material with a structure containing a magnet located underneath the stove top. Such a structure is operatively connected to an appropriate mechanism for regulating the operation of the stove.
Controls of this type are considered undesirable for several reasons. The actuators used with them are capable of being removed from the stove. It is considered that there is a distinct possibility that such actuators may become lost and/or be used as playthings and damaged. Further, structures of this type are considered to be undesirable from a mechanical standpoint because of their complexity and the like.
However, it is considered that such structures are in a sense desirable in that they provide a means whereby the operation of a stove can be achieved from above an impervious surface. This has the advantage that the surface can serve to electrically isolate the functioning parts of such a stove from the magnet control utilized above such a surface. This is particularly important in household type applications where there is always significant danger of items being spilled on a stove or cook top as the stove or cook top is operated.